1. Field of the Invention
The invention relates generally to the field of computerized networks. The invention relates more specifically to the problem of managing a system having a variety of file storage and file serving units interconnected by a network.
2. Cross Reference to Related Applications
The following copending U.S. patent application(s) is/are assigned to the assignee of the present application, is/are related to the present application and its/their disclosures is/are incorporated herein by reference:
(A) Ser. No. 08/151,525 [Attorney Docket No. CONN8675] filed Nov. 12, 1993 by Guy A. Carbonneau et al and entitled, SCSI-COUPLED MODULE FOR MONITORING AND CONTROLLING SCSI-COUPLEDHAID BANK AND BANK ENVIRONMENT;
3. Description of the Related Art
Not too long ago, mainframe computers were the primary means used for maintaining large databases. More recently, database storage strategies have begun to shift away from having one large mainframe computer coupled to an array of a few, large disk units or a few, bulk tape units, and have instead shifted in favor of having many desktop or mini- or micro-computers intercoupled by a network to one another and to many small, inexpensive and modularly interchangeable data storage devices (e.g., to an array of small, inexpensive, magnetic storage disk and tape drives).
One of the reasons behind this trend is a growing desire in the industry to maintain at least partial system functionality even in the event of a failure in a particular system component. If one of the numerous mini/micro-computers fails, the others can continue to function. If one of the numerous data storage devices fails, the others can continue to provide data access. Also increases in data storage capacity can be economically provided in small increments as the need for increased capacity develops.
A common configuration includes a so-called "client/server computer" that is provided at a local network site and has one end coupled to a local area network (LAN) or a wide area network (WAN) and a second end coupled to a local bank of data storage devices (e.g., magnetic or optical, disk or tape drives). Local and remote users (clients) send requests over the network (LAN/WAN) to the client/server computer for read and/or write access to various data files contained in the local bank of storage devices. The client/server computer services each request on a time shared basis.
In addition to performing its client servicing tasks, the client/server computer also typically attends to mundane storage-management tasks such as keeping track of the amount of memory space that is used or free in each of its local storage devices, maintaining a local directory in each local storage device that allows quick access to the files stored in that local storage device, minimizing file fragmentation across various tracks of local disk drives in order to minimize seek time, monitoring the operational status of each local storage device, and taking corrective action, or at least activating an alarm, when a problem develops at its local network site.
Networked storage systems tend to grow like wild vines, spreading their tentacles from site to site as opportunities present themselves. After a while, a complex mesh develops, with all sorts of different configurations of client/server computers and local data storage banks evolving at each network site. The administration of such a complex mesh becomes a problem.
In the early years of network management, a human administrator was appointed for each site to oversee the local configuration of the on-site client/server computer or computers and of the on-site data storage devices.
In particular, the human administrator was responsible for developing directory view-and-search software for viewing the directory or catalog of each on-site data storage device and for assisting users in searches for data contained in on-site files.
The human administrator was also responsible for maintaining backup copies of each user's files and of system-shared files on a day-to-day basis.
Also, as primary storage capacity filled up with old files, the human administrator was asked to review file utilization history and to migrate files that had not been accessed for some time (e.g., in the last 3 months) to secondary storage. Typically, this meant moving files that had not been accessed for some time, from a set of relatively-costly high-speed magnetic disk drives to a set of less-costly slower-speed disk drives or to even slower, but more cost-efficient sequential-access tape drives. Very old files that lay unused for very long time periods (e.g., more than a year) on a "mounted" tape (which tape is one that is currently installed in a tape drive) were transferred to unmounted tapes or floppy disks and these were held nearby for remounting only when actually needed.
When physical on-site space filled to capacity for demounted tapes and disks, the lesser-used ones of these were "archived" by moving them to more distant physical storage sites. The human administrator was responsible for keeping track of where in the migration path each file was located. Time to access the data of a particular file depended on how well organized the human administrator was in keeping track of the location of each file and how far down the chain from primary storage to archived storage, each file had moved.
The human administrator at each network site was also responsible for maintaining the physical infrastructure and integrity of the system. This task included: making sure power supplies were operating properly, equipment rooms were properly ventilated, cables were tightly connected, and so forth.
The human administrator was additionally responsible for local asset management. This task included: keeping track of the numbers and performance capabilities of each client/server computer and its corresponding set of data storage devices, keeping track of how full each data storage device was, adding more primary, secondary or backup/archive storage capacity to the local site as warranted by system needs, keeping track of problems developing in each device, and fixing or replacing problematic equipment before problems became too severe.
With time, many of the manual tasks performed by each on-site human administrator came to be replaced, one at a time on a task-specific basis, by on-site software programs. A first set of one or more, on-site software programs would take care of directory view-and-search problems for files stored in the local primary storage. A second, independent set of one or more, on-site software programs would take care of directory view-and-search problems for files stored in the local secondary or backup storage. Another set of one or more, on-site software programs would take care of making routine backup copies and/or routinely migrating older files down the local storage migration hierarchy (from primary storage down to archived storage). Yet another set of on-site software programs would assist in locating files that have been archived. Still another set of independent, on-site software programs would oversee the task of maintaining the physical infrastructure and integrity of the on-site system. And a further set of independent, on-site software programs would oversee the task of local asset management.
The term "task-segregation" is used herein to refer to the way in which each of the manual tasks described above has been replaced, one at a time by a task-specific software program.
At the same time that manual tasks were being replaced with task-segregated software programs, another trend evolved in the industry where the burden of system administration was slowly shifted from a loose scattering of many local-site, human administrators ----one for each site----to a more centralized form where one or a few human administrators oversee a large portion if not the entirety of the network from a remote site.
This evolutionary movement from local to centralized administration, and from task-segregated manual operation to task-segregated automated operation is disadvantageous when viewed from the vantage point of network-wide administration. The term "network-wide administration" is used here to refer to administrative tasks which a human administrator located at a central control site may wish to carry out for one or more client/server data storage systems located at remote sites of a large network.
A first major problem arises from the inconsistency among user interfaces that develops across the network. In the past, each local-site administrator had a tendency to develop a unique style for carrying out man-to-machine interactions. As a result, one site might have its administrative programs set up to run through a graphical-user interface based on, for example the Microsoft Windows.TM. operating environment, while another site might have its administrative programs running through a command-line style interface based on, for example the Microsoft DOS 6.0.TM. operating system or the AT&T UNIX.TM. operating system. A network-wide administrator has to become familiar with the user interface at each site and has to remember which is being used at each particular site in order to be able to effectively communicate with the local system administrating software programs. Inconsistencies among the interfaces of multiple network sites makes this a difficult task.
Another problem comes about from the task-segregated manner in which local administrative programs have developed over the years. A remote human administrator (or other user) has to become familiar with the local topology of each network site when searching for desired files. In other words, he or she has to know what kinds of primary, secondary, backup and archive storage mechanism are used at each site, how they are connected, how data files migrate through them, and which "file manager" program is to be used to view the files of each type of storage mechanism.
More specifically, if a file cannot be found in the directory of a primary storage device located at a particular network site, the administrator has to switch from the primary storage viewing program to a separate, migration-tracking program to see if perhaps the missing file has been migrated to secondary or archive storage at that site. The administrator may have to switch to a separate, backup-tracking program to see if a file that is missing from primary and secondary storage might be salvaged out of backup storage at the same or perhaps a different site. Sometimes, the administrator may wish to see a historical profile of a file in which revisions have been made to the file over a specified time period. A separate file-history tracking program at the site might have to be consulted, if it exists at all, to view such a historical profile.
If a file cannot be found at a first site then perhaps a copy might be stored at another site. To find out if this is the case, the administrator has to log out of the first site, log-in to the system at a next site and repeat the above process until the sought after data is located or the search is terminated.
Each switch from one site to a next, and from one independent file-managing program to another disadvantageously consumes time and also introduces the problem of inconsistent user interfaces.
A similar set of problems is encountered in the overseeing of lower-level infrastructure support operations of a networked data storage system. Included in this category are the scheduling and initiation of routine file backup and file migration operations at each site, the tracking of problems at each site and so forth.
A method and system for integrating all the various facets of system administration on a network-wide basis is needed.